This invention relates to pressure responsive spring gauges for measuring pressure, temperature or the like, and more particularly is an improvement of the spring element made from cold worked metal which is the subject of my U.S. Pat. No. 4,191,056, issued Mar. 4, 1980, the disclosure of which I incorporate herein by reference.
In my U.S. Pat. No. 4,191,056, I describe a spring element of the Bourdon tube variety, made by compressing the conventionally flattened walls of a metal tube to a reduced thickness to increase its yield strength and provide it with a spring temper. Such a gauge can be fabricated from a relatively inert metal, and particularly from stainless steel, and provides an inexpensive solution to a broad range of difficult applications wherein previously the pressurized fluid had a tendency to react with the thin-walled metal causing the tube to develop leaks.